Selective well treating and gravel packing apparatus

ABSTRACT

The apparatus and method provides the ability to selectively treat a producing zone in a well and to gravel pack an annulus in the well casing outside a screen type liner pipe. A tubing string extending from the surface of the well bore is connected to a packer by a crossover valve. Flow down the tubing string is directed to an annulus below the packer, then inwardly through the screen type liner, then upward through the crossover into the annulus above the packer and then to the earth&#39;&#39;s surface. Communication from the crossover to the annulus above the packer may be selectively closed to permit a treating pressure to be exerted down the tubing to force a treating fluid into the producing zone. The treating pressure is isolated from the casing above the packer to protect the casing above the packer.

United States Patent [191 Abney et al.

SELECTIVE WELL TREATING AND GRAVEL PACKING APPARATUS Inventors: Dave L. Abney; Robert C. Williams,

both of Dallas, Tex.; Horace E. Gilbert, Gretna, La.

Assignee: Dresser Industries, Inc., Dallas, Tex.

Filed: Nov. 1, 1971 Appl. No.: 194,228

US. Cl 166/51, 166/143, 166/184, 166/278 Int. Cl. E2lb 43/04, E21b 43/10 Field of Search 166/51, 278, 224, 205, 166/143, 183, 184,133,131

References Cited UNITED STATES PATENTS [111 3,818,986 [451 June 2 5, 1974 7/1967 Brown 166/278 12/197] Miller 166/278 1/1973 Young et a1v 166/278 ABSTRACT The apparatus and method provides the ability to selectively treat a producing zone in a well and to gravel pack an annulus in the well casing outside a screen type liner pipe. A tubing string extending from the surface of the well bore is connected to a packer by a crossover valve. Flow down the tubing string is directed to an annulus below the packer, then inwardly through the screen type liner, then upward through the crossover into the annulus above the packer and then to the earths surface. Communication from the crossover to the annulus above the packer may be selectively closed to permit a treating pressure to be exerted down the tubing to force a treating fluid into the producing zone. The treating pressure is isolated from the casing above the packer to protect the casing above the packer.

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SHEET 6 0F 6 INVENTORS DAVID L. ABNEY ROBERT C. WILLIAMS HORACE E. GlLBERT w smd AGENT SELECTIVE WELL TREATING AND GRAVEL PACKING APPARATUS BACKGROUND OF THE INVENTION The field of the invention relates to treating and gravel packing oil and gas and other types of wells. Some producing wells contain producing zones that have loose sand. Flow of the desired liquid or gas from such zones into the well bore often carries undesirable amounts of sand which can cause erosion of the equipment and can cause plugging of the flow passages. It has been found that provision of a screen pipe within the perforated producing zone with suitable small size holes or slots provided in the screen pipe and having the annulus between the screen pipe and the casing filled with a suitable size gravel of a predetermined screen size allows passage of the desired fluids from the producing zone and prevents passage of the same. Pro ducing zones also sometimes require treatment in order to increase the area of flow passages to the well bore to permit greater drainage of the producing zone into the well bore. It is sometimes desired to treat a producing zone with acid or another fluid to increase the productivity of the zone.

The prior art includes crossover arrangements whereby gravel can be pumped into an annulus between a screen pipe and the casing by providing a crossover flow arrangement communicating a tubing string to an annulus below a packer outside a screen pipe and providing a return passage through the packer communicating with the annulus outside the tubing above the packer. The prior art in treating producing zones with acid or other fluids includes a simple or heavy duty packer connected to a tubing string allowing the treating fluid to be pumped to an area adjacent the producing zone, allowing displaced fluid to return around an unset packer or through an open valve in the tubing string providing communication between the tubing and the casing above the packer. However, it has heretofore been unknown in the'art to provide a single apparatus selectively capable of performing both functions.

It is therefore an object of this invention to provide an apparatus for selectively treating and gravel packing a well.

It is a further object of this invention to provide apparatus and method for gravel packing and treating a well without removing the tubing between the treating and gravel packing operations.

It is a still further object of this invention to provide apparatus and method for acidizing and gravel packing a producing zone in a well.

It is a still further object of this invention to provide completely retrievable apparatus for treating and gravel packing a producing zone in a well.

It is a still further object of this invention to provide a selectively operable apparatus for treating and gravel packing a well without imposing the pressure required for treating the zone on the casing above the packer.

SUMMARY OF THE INVENTION These and other objects of the invention are achieved by methods and apparatus for use in a well casing in a well bore includinga packer anchored in the well casing and a tubing string extending from the surface of the well bore through the packer, wherein an upper portion of the tubing forms an upper annulus and a lower portion of the tubing below the packer forms a lower annulus, including a screen pipe connected to and communicating the lower tubing string portion to the lower annulus, and a crossover valve arrangement for communicating the upper tubing string portion to the lower annulus and for selectively communicating the lower tubing string portion to the upper annulus and for selectively preventing communication between the lower tubing string portion and the upper annulus.

DESCRIPTION OF THE DRAWING FIG. I is a schematic illustration, partially in elevation and partially in section, showing an apparatus according to this invention.

FIG. 2 is an enlarged view of a portion of the apparatus as illustrated in FIG. 1.

FIG. 3 is an elevation showing the jay-slot on mandrel of FIG. 2.

FIG. 4 is a view, partially in elevation and partially in section, of the crossover valve of FIG. 2 shown in the closed position.

FIG. 5 is a schematic view, partially in elevation and partially in section, illustrating an alternate embodiment according to this invention.

FIGS. 6A and 6B are schematic views of a well completion with still another alternate embodiment according to this invention.

FIG. 7 shows an enlarged portion of the apparatus of FIG. 6 with some parts operably repositioned.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, a well bore is illustrated with a well casing 10 in place. A packer I2 having a seal bore 14 is anchored in sealing engagement with the casing 10. A tubing string 18 extends from the surface of the the ' well bore and is in engagement with a crossover valve nipple I6 and a lower portion 44 of tubing string 18, a

seal nipple 58 and a collet are threadedly connected into an assembly. The crossover valve assembly has a housing 22 connected to the tubing string 18. A mandrel 24 is disposed in a rotatable and slidable relation to the housing 22. The axial movement and rotation of the housing 22 on mandrel 24 is controlled by a jay-pin 26 threadedly engaged to housing 22 and cooperating with jay-slot 28 formed in the outside of mandrel 24. The crossover valve is illustrated in the open position communicating a port 30 in the housing with passage 36 in the mandrel. A crossover 34 is disposed in sealing engagement with mandrel 24 and having passages 36 and 38 communicating with port 30. An inner tubing string 40 is connected with passage 38 in crossover 34 and extends to a barrier 42 in a lower portion 44 of tubing string 18. A suitable seal 46 seals the lower end of tubing string 40 to barrier 42. A tubular extension or tubing string 48 is attached to the barrier 42 to extend the passageway in tubing string 40, the lower end of tubing string 48 having a bottom opening 49 to allow fluid communication between screen pipe 74 and the tubing string 48. The lower portion 44 of tubing string 18 has at least one port 50 abovethe barrier 42. A tubing string S2'is suspended below packer 12. At least while picking up the tubing string will move the jay-pin 26 to position 260 and close the crossover valve as illustrated in FIG. 4. Pressure is then applied down the tubing string 18 to force the treating fluid, for example, acid, into the producing zone 72. The pressure required to force the fluid into the producing zone is imposed through the slots 76 in the screen pipe 74 and into the tubing string 48, the tubing string 41), the passage 38 and the passage 36. Communication to the annulus above the packer is prevented by the seals 23 and 29 in engagement with the seal bore 27 in the valve.

It is desirable to avoid imposing a treating pressure on a casing string above the producing zone because the casing commonly has less pressure capability than a tubing string. Also since the casing is permanently installed in the well, erosion and corrosion may significantly reduce the pressure capability of the casing during the life of the well. Therefore, a casing string might rupture if a treating pressure were imposed against the inside of the casing.

Once the treating fluid has been pumped into the producing zone, the crossover valve may be opened by lowering tubing string 18 to its lowermost position in the well casing positioning jay-pin 26 in position 26a or 26b as illustrated in FIG. 3. The angular portion of jayslot 28 will guide jay-pin 26 from position 260 to position 260 upon axial movement of the housing 22 on the mandrel 24. Communication is then established between the crossover passage 38, passage 36 and housing port communicating the producing zone with the annulus above the packer. A mixture of gravel and fluid such as water may then be pumped down the tubing. The mixture will flow down through passage 37, through annular passage 39 and out the ports 50 and 54 into the lower annulus 78 outside the tubing string 52 below the packer. The fluid will pass through slots 76 in the screen pipe but the gravel will be of a predetermined size large enough that the gravel particles will not pass through the screen pipe and the gravel will be deposited in the annulus between screen pipe 74 and casing 10 adjacent the producing zone. The fluid with which the gravel was pumped into position will pass on through slots 76 in the screen pipe and up through the tubing string 48 and the tubing string through the passages 38 and 36 through the port 30 into the upper annulus where fluid is returned to the surface of the' well bore.

As an optional feature of the invention, after the gravel is placed, the tubing may be lifted to disengage the seal nipple 16 from the seal bore 14 and be lifted sufficiently to engage the collet 60 with groove 66 with valve 20 in the open position. Fluid may then be pumped down the casing annulus to pass down through seal bore 14 down through the annulus between the lower portion 44 of the tubing string and the tubing string 52 and pass into the tubing string 44 through the port where flow can proceed upward through passage 37 and upward to the surface of the well through tubing string 18. Debris in the upper annulus of the casing and on top of packer 12 may thereby be entrained by the fluid and displaced upwardly through the tubing string 18 to the surface of the well bore.

DESCRIPTION OF THE ALTERNATE Referring to FIG. 5, a well bore is illustrated with a well casing 110 intersecting a producing zone 172. A packer 112 having a seal bore 114 is anchored in sealing engagement with the casing 110. A tubing string 118 extends from the surface of the well bore and is in engagement with a crossover valve assembly shown generally at 120. A seal nipple 116 is located in sealing engagement with seal bore 114 by a shoulder 181. The crossover valve 120, the shoulder 181, a seal nipple 116 and a lower portion 144 of tubing string 118, a seal nipple 158 and a collet 160 are threadedly connected into an assembly. The crossover valve assembly has a housing 122 connected to the tubing string 118. A mandrel 124 is disposed in a rotatable and slidable relation to the housing 122. The axial movement and rotation of the housing 122 on mandrel 124 is controlled by a jay-pin 126 threadedly engaged to housing 122 and cooperating with jay-slot 128 formed in the outside of mandrel 124. The crossover valve is illustrated in the open position communicating a port 130 in the housing with port 136 in the mandrel.

ln the position shown in F IG. 5, housing ports 130 are in communication with ports 136 in the wall of mandrel 124. A barrier 142 is positioned in sealing engagement in mandrel 124 above mandrel ports 136. An inner tubing string is sealingly engaged to barrier 142. Tubing string 144 extends below crossover valve 120. The shoulder 181 is provided on the lower tubing string 144 to locate the tubing with respect to the packer 112 and to locate seal nipple or seal assembly 116 in sea] bore 114 in packer 112. Crossover 134 is positioned inside lower string 144 and provides a port 136 which communicates with the port 154 in lower tubing string 152 which is suspended below packer 1'12. Tubing string 140 extends to and seals in crossover 134 and communicates with passage 138 in crossover 134. An inner tubing string 1411 is connected with passage 138 in crossover 134 and extends to a barrier 142 in the mandrel 124. A tubular extension 148 may be attached to a barrier 149 to extend communication to the passageway 137. The lower portion 144 of tubing string 118 has at least one passage 150 in the crossover 134. A tubing string 152 is suspended below packer 112. At least one port 154 in tubing string 152 is in communication with the passage 150. A sea] bore 156 is provided inside the tubing string 152. The seal nipple or seal assembly 158 is provided in sealing engagement with the seal bore 156. The collet 160 is a tubular member with axial slots 162 and is provided with an enlarged portion engaging a groove 164 in the tubing string 152. The collet 160 is a heat treated spring member which is deformable to expand into engagement with the groove 164 and deformable to a smaller diameter upon upward axial thrust to engage groove 166. The tubing string 118 may be located at a position upward from that shown in FIG. 1 so that the collet 160 can engage a groove 166 which is positioned to locate the seal nipple 116 above the seal bore 114 in the packer 112. The casing 110 is provided with a multiplicity of perforations 170 to communicate with the producing zone 172 to allow oil and/or gas production to flow into the casing 110. The tubing string 152 is provided with a screen pipe 174 which has a multiplicity of small holes or slots 176. A lower annulus 178 is formed between the casing 110, and the tubing string 152 and the screen pipe 174.

This apparatus provides the ability to place into the lower annulus 178 particles of rock called gravel 180 t which is of a selected screen size large enough to be retained by the holes or slots 176 and to allow passage of tubing string 148 upwardly through the passage 137 and upward inside lower portion 144 of tubing string 118 external of tubing string 140 and through ports 136 and 130 into the annulus above the packer where the fluid may be conducted upwardly to the surface of the well bore.

Referring now to FIGS. 6A and 6B, this alternate embodiment utilizes a hydraulic set packer and provides an installation which is completely retrievable. All of the apparatus is assembled and lowered into the well bore on the tubing string 218 until the slots 276 and the screen pipe 274 are substantially at the same depth as casing perforations 270. The hydraulic packer is set by exerting hydraulic pressure inside the tubing stn'ng 218. Sea] sleeve 284 is in sealing engagement in annular passageway 239 as hereinbefore described. The setting pressure exerted down tubing string 218 is communicating through passage 292 and annular passageway 293 to the interior of the packer 212. This pressure differential causes the packer 212 to seal and grip the casing by causing piston slips 294 to expand to grip the casing 210. Hydraulic cylinder 295 is responsive to the described pressure differential to compress packing elements 296 into sealing engagement with the casing. The downward thrust from a cylinder 295 is supported by slips 297 which are expanded into gripping engagement with the casing 210 by tapered expander 298. Mechanical locking devices 299 and 300 hold the hydraulic packer in set position.

Setting pressure exerted down tubing string 218 to accomplish the setting of hydraulic packer 212 is sealed by seal sleeve 284 which is supported in sealing position by frangible shear screws 301. These frangible parts have a predetermined strength to support a predetermined pressure differential from tubing string 218.

Application of sufficient pressure to shear screws 301 removes support for sleeve 284 in the position shown in FIG. 7 and the pressure causes sleeve 284 to move downwardly to the position shown in FIG. 6A so that communication from annulus 239 is established external of tubing string 240 to ports 250 and 254.

After the hydraulic set packer 212 is anchored in sealing engagement to the well casing 210, the well treating and gravel packing operations can be carried out as hereinbefore described using the crossover valve 220. After gravel 280 has been placed in the annulus 278, the tubing string 218 and crossover valve assembly 220 and seal nipple 213 can be released from the tubular extension 215 and seal bore 214 to permit retrieval of the tubing string 218, crossover valve 220 and the associated equipment leaving the packer 212, the lower tubing string 252 and the screen pipe 274 in place.

If it is desired to retrieve the packer 212 and the remainder of the equipment in the well, the gravel can be circulated back in a reverse manner from the method by which it was positioned by opening crossover valve 220 and pumping fluid down the upper casing annulus above the packer to enter housing port 230, through crossover passage 236 and down tubing string 240, out the screen pipe slots 276 to pick up the gravel 280 and return it up through ports 254 and 250, up through the annulus external to tubing string 244 and passage 237, and upward through tubing string 218 to the surface of the well bore. After a substantial portion of the gravel has been removed, the entire apparatus may be retrieved by lifting upwardly with tubing string 218 to release the hydraulic packer 212 from the sealing engagement with the well casing in a manner more fully described in US. Pat. No. 3,209,831. The packer 212 may be released from the well casing and the entire apparatus may be retrieved.

It should thus be appreciated that there has been described and illustrated herein the preferred embodiments of the invention. However, various modifications of these embodiments will occur to those skilled in the art. For example, the invention contemplates that those skilled in the art may desire to first acidize or otherwise treat the well and then gravel pack the formation of interest. The invention also contemplates the gravel packing of the formation and then the further treatment of the well. Likewise, the invention contemplates that the gravel packing material may be recovered from the well at any time so desired.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. Apparatus for treating a well having a casing comprising:

a first tubing string extending to the surface of the well bore;

a second tubing string inside a portion of said first tubing string and forming an annular passageway therebetween;

a packer anchored in the well casing and having a seal bore;

a third tubing string connected to and extending below said packer and having a side port, and a seal bore below said side port, and having a screen below said seal bore;

valve means communicating with said first tubing string comprising an inner tubular mandrel having side ports,

a tubular housing having side ports, and encircling said inner mandrel,

said tubular housing being axially slidable on said inner mandrel,

releasable means for locking said housing and said mandrel in a first axial position and for allowing said mandrel and housing to move to a second axial position,

seal means for allowing communication between said mandrel side ports and said housing side ports in one said axial position and for preventing communication between said mandrel side ports and said housing side ports in said other axial position, and

a crossover in said tubular mandrel having a first passage communicating said mandrel ports to said second tubular string and having a second passage communicating said tubular mandrel above said mandrel side ports to said tubular mandrel below said side ports;

a first seal nipple communicating with said mandrel in said valve means, and sealingly engageable with said seal bore in said packer;

a tubular extension below and communicating with said first seal nipple, and having an opening;

a second seal nipple communicating with said tubular extension and sealingly engageable with said seal bore in said third tubing string; and

a barrier in said tubular extension below said opening, sealingly engaging said tubular extension and said second tubing string.

2. Apparatus according to claim 1 wherein said seal means allows communication between said mandrel side ports and said housing side ports in said first axial position.

3. Apparatus for use in a well bore having a packer anchored in a well casing, a tubing string from the surface of the well bore extending through the packer and sealingly engageable with the packer to form an upper annulus above the packer and a lower annulus below the packer, the improvement comprising:

crossover means in the tubing string for communicating the tubing string above the packer with the lower annulus and communicating the tubing string below the packer to the upper annulus;

means communicating said lower annulus with said tubing string below said packer;

valve means for selectively preventing communication in said crossover means from the tubing string below the packer to the upper annulus, said valve means comprising:

a mandrel having side ports;

a housing movable axially on said mandrel to a first position and to a second position and having ports;

seal means for selectively preventing communication through said mandrel side ports when said housing is in said first position and for selectively communicating from said mandrel side ports through said housing side ports when said housing is in said second position;

releasable means for selectively locking said mandrel and said housing in one of said first or said second positions and for allowing said mandrel and said housing to move to the other of said first or said second positions; and

means for releasably holding said mandrel in said packer, said holding means adapted for holding said mandrel in said packer in a sealing relationship in a first position of said holding means, and adapted for holding said mandrel out of sealing engagement with said packer in a second position, thereby allowing fluid to bypass said packer, said releasing means further adapted to operate between said first and second positions an indefinite number of times.

4. Apparatus according to claim 3 wherein said releasable means locks said mandrel and said housing in said second position and allows said mandrel and said housing to move to said first position.

5. Apparatus according to claim 4 wherein said releasable means locks said mandrel and said housing in said second position upon movement of said mandrel and said housing to said second position.

6. Apparatus according to claim 5 wherein said releasable means comprises:

a jay-slot in one of said mandrel or said housing; and

a cooperating jay-pin in the other of said mandrel or said housing.

7. The apparatus of claim 3 wherein said releasing means further comprises spring collet means on said mandrel and a plurality of collet grooves in said packer arranged to releasably engage said spring collet means. 

1. Apparatus for treating a well having a casing comprising: a first tubing string extending to the surface of the well bore; a second tubing string inside a portion of said first tubing string and forming an annular passageway therebetween; a packer anchored in the well casing and having a seal bore; a third tubing string connected to and extending below said packer and having a side port, and a seal bore below said side port, and having a screen below said seal bore; valve means communicating with said first tubing string comprising an inner tubular mandrel having side ports, a tubular housing having side ports, and encircling said inner mandrel, said tubular housing being axially slidable on said inner mandrel, releasable means for locking said housing and said mandrel in a first axial position and for allowing said mandrel and housing to move to a second axial position, seal means for allowing communication between said mandrel side ports and said housing side ports in one said axial position and for preventing communication between said mandrel side ports and said housing side ports in said other axial position, and a crossover in said tubular mandrel having a first passage communicating said mandrel ports to said second tubular string and having a second passage communicating said tubular mandrel above said mandrel side ports to said tubular mandrel below said side ports; a first seal nipple communicating with said mandrel in said valve means, and sealingly engageable with said seal bore in said packer; a tubular extension below and communicating with said first seal nipple, and having an opening; a second seal nipple communicating with said tubular extension and sealingly engageable with said seal bore in said third tubing string; and a barrier in said tubular extension below said opening, sealingly engaging said tubular extension and said second tubing string.
 2. Apparatus according to claim 1 wherein said seal means allows communication between said mandrel side ports and said housing side ports in said first axial position.
 3. Apparatus for use in a well bore having a packer anchored in a well casing, a tubing string from the surface of the well bore extending through the packer and sealingly engageable with the packer to form an upper annulus above the packer and a lower annulus below the packer, the improvement comprising: crossover means in the tubing string for communicating the tubing string above the packer witH the lower annulus and communicating the tubing string below the packer to the upper annulus; means communicating said lower annulus with said tubing string below said packer; valve means for selectively preventing communication in said crossover means from the tubing string below the packer to the upper annulus, said valve means comprising: a mandrel having side ports; a housing movable axially on said mandrel to a first position and to a second position and having ports; seal means for selectively preventing communication through said mandrel side ports when said housing is in said first position and for selectively communicating from said mandrel side ports through said housing side ports when said housing is in said second position; releasable means for selectively locking said mandrel and said housing in one of said first or said second positions and for allowing said mandrel and said housing to move to the other of said first or said second positions; and means for releasably holding said mandrel in said packer, said holding means adapted for holding said mandrel in said packer in a sealing relationship in a first position of said holding means, and adapted for holding said mandrel out of sealing engagement with said packer in a second position, thereby allowing fluid to bypass said packer, said releasing means further adapted to operate between said first and second positions an indefinite number of times.
 4. Apparatus according to claim 3 wherein said releasable means locks said mandrel and said housing in said second position and allows said mandrel and said housing to move to said first position.
 5. Apparatus according to claim 4 wherein said releasable means locks said mandrel and said housing in said second position upon movement of said mandrel and said housing to said second position.
 6. Apparatus according to claim 5 wherein said releasable means comprises: a jay-slot in one of said mandrel or said housing; and a cooperating jay-pin in the other of said mandrel or said housing.
 7. The apparatus of claim 3 wherein said releasing means further comprises spring collet means on said mandrel and a plurality of collet grooves in said packer arranged to releasably engage said spring collet means. 